Preheat the oven to 190 C / Gas 5.
Cream the margarine and sugar until light and fluffy.
Beat in the eggs and vanilla. Beat well.
Fold in the flour and baking powder, beating well to combine.
Add the milk. The mixture may be a bit sloppy, but that is fine, do not add more flour to dry it up! Turn the mixture into two lined sandwich tins.
Bake until a skewer inserted near the centre comes out clean, about 15 minutes.
Turn out onto a wire rack to cool and then sandwich together with raspberry jam and cream.